Thermometric apparatus



June 26, 1945. M. A. Pl CClANO THERMOMETRIC APPARATUS Filed March 4, 1944 a Sheets-She t 1 w R m m a N ..LY i P A m m ma 7 5% Hm? L wm w II m I June 26, 1945. M. A. PICCIANO THERMOMETRIC APPARATUS Filed March 4, 1944 3 Sheets-Sheet 2 June 26, 1945. M. A. PICCIANO THERMOMETRIC APPARATUS Filed March 4, 1944 3 Sheets-Sheet 3 O. I R V C H 00k .flw Mm s N .L M \l D. I J Wm OOH @VOQQ .QMJ g LIN H & W7 Z E m. MW. Q. lW 5% w N 2 M I I x wWW T 1, M. iv .7 v i I! un l l fdflmx d h l lll 1 ab Nb 6.0 Q. i m% an @m MN QN UUrN Wm mm mm NQ //AT J [1 l .1... .r .2, a x 1 4 Mb Nb b 9% mm mw Q on wN rN Patented June 26, 1945 "UNITED" STAT PATENT OFFICE;

Breeze Corporations, Inc.,.Newark,

poration. of New Jersey Application March 4, 1944, Serial No. 525,086

2 Claims.

This invention relates to thermometric apparatus, and more specifically to such as are adapted to connote the temperature within the cylinder of an internal combustion engine.

I It is an object of this invention to provide a heat indicator in which the responsive medium is a coil of exceedingly fine wire of high resistivity and positive temperature co-eflicient; or a compound resistor material having a positive or negative temperature co-efii'cient of resistivity may be used instead of wire.

A further feature is in the provision of a heat conducting apparatus adapted to have its sensitive contacting element partially embedded in or in close contact with the part where it is directly subjected to heat emanations, without the interposition of extraneous and unnecessary elements. I 4' Another purpose is to produce a simple re sistance device, easily installed and prov-id'ecl'with guarding means whereby the operative parts are protected from stray electric currents, as well as from contact with parts which may interfere with its efiicient operation. 1

These and analogous objects are accomplished by the novel and practical construction, combination and arrangement of parts hereinafter described and illustrated in the accompanying drawings, constituting a graphical component of this disclosure, and in which:

Figure l is a side elevational view of an embodiment of the device.

Figure 2 is a longitudinal sectional view taken Q on line 2-2 of Figure 1.

Figure 3 is a front end view of the apparatus.

Figure 4 is a rear view of thesame.

Figure 5 is a transverse sectional view taken on line 55 of Figure 2, drawn to an enlarged scale.

Figure 6 is a similar sectional view, taken on line 6-6 of Figure 2.

Figure 7 is a partial side, partial sectional view of the forward end of the device in which discs somewhat smaller than the tip are shown to provide clearance.

Figure 8, is a fragmentary perspective view showing the insulated conductors.

Figure 9 is a perspective view of a detail in construction.

Figure 10 is a side elevational view of a modifled form of the apparatus, showing one form of the resistatory circuit.

Figure 11 is a longitudinal'sectional view of the same.

Figure 12 is a transverse sectional view, taken on line l2-I2 of Figure 10.

N. J-., a cor- Referring to the drawings, Figures 1 to. 9,

wherein one form of the invention is illustrated,-

are beveled at approximately thirty degrees, as

shown.

The main portion of the shell is supported in a pair of spaced bearings '2'l--22, having caps'23, and connected integrally by a unitary bracket 24, arranged to support the structure relative to the object. 4

A collar 25 on the shell 20, adjacent the inner side Of the front bearing 2|, is pressed towards the object Hiby ahelical' spring 26 surrounding the shell 20, its opposite end abutting the-rear bearing 22.

Rearward' of the tip body 16, in the counterbore l8, are frontand rear ceramic discs 21-28 of lesser diameter than the tip I 6, each having two passages 29--3ll equally spaced from the center, and leading therefrom are slots 3 I32 terminating in a concentric circular groove 33 formed equally in each disc.

A washer 34, made of asbestos or like nonconductive resilient material, is interposed between the inner disc 28 and shoulder at the bottom of the counterbore I8. I

A coil 35 of small diameter (.0015") made 0 alloy wire, quickly responsive to temperature changes, of high resistivity and positive temperature co-efiicient, is contained within the groove 33, its ends connected with the bent over portions .of conductors 38-39 disposed in the transverse slots 3I32; the conductors 38-39 passing in spaced relation through the openings in the rear disc 28, and washer 34 into the main bore 40 ofthe shell 2|]. In assembling the coil and discs,

ceramic cement is spread along the walls of grooves 33 into which the coil 35 is inserted.

When the discs 21 2s are pressed together some of this cement spreads out along the meeting faces of the discs so that upon the hardening of the cement, the discs and coil are firmly bound together into an integral unit. By means of this construction, the heat developed in the coil, due to thepassage of electrical current therethrough,

is rapidly dissipated and any substantial increase in temperature of the coil by such current is obviated.

By providing a clearance space between the periphery of the discs and the counterbore l8, the conduction of heat inwardly to the coil from the portion of the shell 20 surrounding the discs is substantially eliminated so that the coil responds to temperature variations of the tip.

The main conductors 38--39 are encased in individual insulative tubes 4l-42 around which is a body of insulative cement 43, completely filling the bore 40 of the shell, the conductors extending outward at thir ends to connect with the termin-als of a circuit leading to an indicating meter.

In the modified form, shown in Figures 10 to 12, the apparatus is shown as attached to a fragmentary portion of an internal combustionengine cylinder 45, equipped with a spark plug 46, and in which operates a piston 41. The side wall of the cylinder is provided with a bore 48 having a threaded counterbore 48' into which the end of a tubular adapter 54 is screwed, although the opening may be formed in the cylinder head or other preferred part of the engine cylinder to produce equivalent results.

A tip 49 is mounted in a shell 50, the pointed end of the tip seating against the bottom of the opening 48 by the spring 53, while its rear end makes intimate contact with the outermost of a pair of dielectric discs containing between them a coil and conductors exactly as previously described.

Fixed on the stem of the shell 50 is a collar 52 to receive the thrust of a compression spring 53 encircling the stem, all these several elements being encased in the tubular adapter 54 which is provided, near its outer end, with a fixed headed pin 55.

A cup shaped collar 56 is bored to receive and turn on the end of the adapter 54 and provided with a well known type of bayonet joint slot 51 adapted to receive the, head of the pin 55 and retain it in position against the pressure of the spring 53 which abuts the bottom of the collar, the enlarged portion 58 of which is knurled to facilitate manual operation.

Abutting the hub 59 of the collar 58 is a ferrule 60, receptive of the outer end of the stem 5| and bored to receive the end of a fiexible metallic tube 6!, extending as far as may be required to act as a guard for an inner tube 62 enclosing aninsulative sheath 63 for the conductors 3839.

These conductors have in their circuit a battery 64 and resistance 65, and lead to an indicator 66 having a scale 61 graduated in degrees centigrade, by which the temperature of the cylinder may be readily ascertained.

Although the foregoing is descriptive of the best known embodiments of the apparatus, it is to be considered as suggestive, rather than exhaustive, as many changes and modifications may be made within the scope of the appended claims.

Having thus described the invention and set forth the manner of its construction and application, what is claimed as new and sought to be secured by Letters Patent of the United States is:

1. A device for ascertaining the degree of heat in the cylinder of an internalcombustion engine, comprising a plug adapted for insertion-in an opening in the wall of the cylinder, a heat-conductive tip disposed in said plug in intimate contact with the cylinder wall, a hollow ste'm extending outwardly from said plug, an insulated coil of fine high resistance wire disposed in said stem and exposed to the temperature changes of said tip, a pair of spaced conductors reaching through said stem, each conductor being in electrical engagement with one of the opposed ends of said coil, an insulative filling for said stem, a metal casing arranged to .be attached to the cylinder wall and encompassing said plug and stem, a collar in which the free end of said casing is inserted, and spring means for biasing the tip into engagement with the cylinder wall, said conductors extending through said collar for ready attachment to an indicator.

2. The device as claimed in claim 1, in which a ferrule abuts said collar, and a flexible protective sheath is secured to said ferrule and adapted to encompass the conductors.

MICHAEL A. PICCIANO. 

